“The OncoExTra® assay (formerly GEM ExTra) is a whole exome, whole transcriptome, tumor-normal genomic profiling assay that is designed to identify somatic (tumor-specific) SNVs, CNAs, indels, gene fusions, and alternative transcripts.“
Cancer treatment is moving toward a more precision-based approach, where therapies are guided not just by the tumor’s location but also by its genetic features. Mutations in cancer cells can point to specific drugs that may be more effective for certain patients. However, detecting these mutations often requires broad and detailed analysis. This is where comprehensive genomic profiling becomes especially important.
One of the main challenges in cancer care is that many existing genetic tools focus on only a limited number of mutations. As a result, some treatment opportunities may be missed. Certain mutations are also difficult to detect because they occur at low levels or exist in complex forms, such as gene fusions. Without advanced screening methods, these changes may go unnoticed.
To address these challenges, researchers from Exact Sciences Corporation conducted a large-scale study using a broad genomic screening approach. The findings were recently published in the journal Oncotarget.
The Study: Using OncoExTra to Analyze Genetic Alterations in Advanced Solid Tumors
In this study, titled “Comprehensive genomic profiling of over 10,000 advanced solid tumors” and led by Jean-Paul De La from Exact Sciences Corporation, researchers used a method called OncoExTra to analyze over 11,000 tumor samples from more than 10,000 patients with advanced solid tumors. The goal was to understand how often genetic alterations that could guide treatment were found using this type of broad assay.
The Results: Actionable Mutations Found in Over 90% of Tumors
The study found that nearly 92 percent of the tumor samples contained at least one genetic alteration that could potentially guide treatment. About half of the samples had mutations that were linked to therapies already approved by the U.S. Food and Drug Administration, either for the cancer type being studied or for other types.
Some of these mutations were found at very low levels, which highlights the need for sensitive screening techniques. Gene fusions, alterations that can be difficult to detect with standard methods, were identified in 7.5 percent of the cases. These fusions are especially relevant in certain cancers like prostate cancer and sarcoma, where they can influence treatment and, in some cases, help clarify the diagnosis.
Mutations were also found in several key biological pathways that are involved in how cancer cells grow, divide, and repair themselves. These included the PI3K/AKT, MAPK, and DNA repair pathways. Changes in these pathways can affect how the cancer behaves and responds to treatment.
In addition, the study reported that about 8 percent of the samples had mutations in the promoter region of the TERT gene. These changes have been associated with increased tumor growth and worse patient outcomes in several cancers. Although there are no approved therapies that directly target these mutations yet, their detection may become more relevant as new treatments are developed.
The Breakthrough: A Genomic Method That Analyzes Both DNA and RNA
The OncoExTra assay stands out for its ability to analyze both DNA and RNA across all known genes. It also compares tumor tissue to the patient’s normal tissue, which helps reduce the risk of false-positive results. This broad and in-depth approach enables the detection of rare, low-level, and complex mutations that smaller screening panels might miss. The method also identifies biomarkers such as tumor mutational burden and microsatellite instability, which can help determine whether a patient is likely to benefit from certain types of immunotherapy.
The Impact: Improving Precision Oncology Through Genetic Insights
These findings suggest that comprehensive genomic profiling can provide valuable information to help guide treatment for patients with advanced cancer. By identifying relevant mutations, clinicians can make more informed decisions, whether that involves prescribing targeted therapies, recommending clinical trials, or confirming a diagnosis. This supports a more individualized approach to cancer care, aiming to match each patient with the most appropriate treatment options based on the biology of their tumor.
Future Perspectives and Conclusion
While further studies are needed to better associate genomic findings with patient outcomes, this research demonstrates the clinical value of comprehensive genomic profiling. As screening methods continue to improve and become more widely available, they may enable more patients to receive treatments guided by the biological features of their tumors rather than tumor location alone.
Overall, the study shows that large-scale genomic screening is both feasible and useful in real-world oncology practice. It supports a more precise and informed approach to cancer care, while underscoring the importance of continued research and careful integration of genomic tools into clinical decision-making.
Click here to read the full research paper published by Oncotarget.
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Oncotarget is an open-access, peer-reviewed journal that has published primarily oncology-focused research papers since 2010. These papers are available to readers (at no cost and free of subscription barriers) in a continuous publishing format at Oncotarget.com.
Oncotarget is indexed and archived by PubMed/Medline, PubMed Central, Scopus, EMBASE, META (Chan Zuckerberg Initiative) (2018-2022), and Dimensions (Digital Science).
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